Pneumatic piano-action.



NNNNNNNNNNNNNNNNNNN APPLICATION. P I L B D M A R l l 9 1 2.

' 1,045,? 1 O. I Patented Nov. 26, 1912.

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WALTER A. KRUCK, 0F CAMDEN, NEW JERSEY.

PNEUMATIC PIANO-ACTION. 1

To all whom itmay concern: 7

Be it known that I, WALTER A. KRUCK, a citizen of the United States, residing at Camden, in the county of Camden and State of New Jersey, have invented certain new and useful Improvements in Pneumatic Piano-Actions, specification.

-This invention relates to pneumatic piano actions, and has for its object the improve-v ment of the invention set forth in ap lication for Letters Patent in the United tates filed April 27, 1911, Serial of which the following is a combining in one structure and position the valve operating and action operating de-' vices, and giving to the various parts there- ;of special construction and arrangement as hereinafter shown and described.

hollow screws C and c,

tral orifice with Figure l of the drawings herewith represents a vertical section of all parts, and Fig. 2 is a top plan of the valve-lifting piston.

The same letter refers to the same part.

Considering the drawings, the support A, which may be of wood, is providedwith the suction cavity a. Upon the base is set the cylindrical cup B, having the hole I; throu h the bottom, and secured to the base b. t e passed throng the bottom of cup B into the base A. A piston is constructed with, usually, a pair of orifices d that movably fit the hollow screws ex ternally, and the rise and fall of the piston is guided by the screws. The piston D is slightly raised on the underside, and, openings, d, are large enough to permit the quick escape of air from beneath the iston. The piston rod e is also a valve rod: having at its upper end the valve F. The top of the cylinder B, in which piston D operates, is closed by the cap 1, and the cap has a cenupset edge to a 0rd a valve seat, designated by numeral 1, for the valve F. It will now be be termed the valve-operating cylinder, and the relatively larger cylinder G, extending above it, may be called the action-operating cylinder. Within cylinder G is a piston g. The cylinder G is closed at the top by a cap H, which is pierced by the air-holes h. Centrally through cap H is passed the air tube .J, and it will be observed that the central movably piston thus arran ed about the tube is desportion of piston lhas an opening made to ignated by the n Specification of Letters Patent. Application filed March 1, 1912. Serial No. 680,900.

excessive entrance of No. 623,614, for pneumatic action for self-playing pianos, by

noted that cylinder B may fit the tu e J. The opening offthe eral 2, and in' practice Patented Nov. 26, 1912.

a small ring of felt 3 may be attached at the said opening 2, encircling tube J to prevent air. A yoke K ofany chosen form pivotally connects the piston g and the action-operating lever is. Piston 9 drops upon the cushion j. The note sheet L passes over the tracker M, and the tracker is connected by tube m with the channel N in the base A, leading to the hole I) in the bottom of valve-operating cylinder B already mentioned.

All the cylinders, cups, caps, andvpistons' are in practice usually of stamped metal.

The operation of this invention may be brought on when an opening of the note sheet registers with a duct in the tracker. Air enters immediately beneath the piston D through the hole I), by reason of the fact that the cylinder B is maintained in a state of partial vacuum through the communication established by the hollow screws C and c with the suction cavity a. The valve F is raised into contact with the lower end of tube J, thus closing cylinder G below piston g to the atmosphere. The air being exhausted beneath piston act-uates lever is. Then the note sheet again covers the duct in the tracker, air is taken from beneath piston D, which can no longer sustain the valve Fin its uppermost position closing tube J, and the valve F. is reseated' in the position shown in the drawing,

and the partiahvacuum in cylinder B and below piston D is reestablished. At the same time air enters tube G below-piston g, which is lifted again into the attitude illustrated. The parts are now ready for a repetition of the operation.

It will be observed that the pistons are without packing; .ln practice they are made to fit the cylinders'movably, but not closely enough to bind, and piston D'is so formed as to permit} the air to escape from below it through the openings d, as freely as may be desired to permit perfect action. Having now described this invention and explained the manner of its operation, what I claim is 1. In a pneumatic piano action, the coinbination with a support having a suction cavity of a valve-operating cylinder arranged "on said support, a piston arranged in said cylinder, a tracker, means constructed to connect the tracker and said cylinder below the piston, means constructed to connect saidrsuction cavity and cylinder 9 it descends and above said piston, means constructed to close the top of said cylinder and provided with a valve seat, a valve arranged to occupy said valve seat, said valve being connected with and operated by said piston, an actionoperating cylinder arranged in axial alinement with said valve-operating cylinder and provided with a piston, an air tube passing through the piston in saidaction-operating cylinder, the lower end of said tube being constructed and arranged as an upper seat for said valve, a. lever, and pivotal connections between the lever and the piston in said action-operating cylinder. 7

2. In a pneumatic action, the combination with a support having a. suction cavity,

ating cylinder arranged in axial alinement with said valve-operating cylinder and provided with a plston, an air tube passing in axial aliuement and each having a piston,

of a tracker, means constructed to connect the tracker and the valve-operating cylinder below its piston, acsuction chamber, means constructed to connect the suction chamber and valve-operating cylinder above its piston, means providedvvith a valve seat and constructed to partition one cylinder from the other, a valve constructed to occupy said seat and connected with the piston in said valve-operating cylinder, an air tube having one end located in said action-operating cylinder below its pistonandarranged as a second seat for said valve, apd a lever pivotally connected withwhe piston in said action-operating cylinder. I

In testimony whereof I afiix my signature in presence of two witnesses.

WALTER A. Kaucrr.

Witnesses:

H. R. GEORGE, Ban S. Brown.

Copies of this patent may be obtained for we cents each, by addressing the Commissioner of latents,

Washington, D. C. 

